Had my 4kW photovoltaic array installed last week. Took two days as it’s a 2kW array on the front of the house facing SE and two 1kW arrays on the back facing NW. Picture shows the front panels

I went for a system where each panel has a separate ‘optimiser’ fitted. Reason for this is that I was surprised to find that normal systems are connected in series so if one panel fails or is underperforming then the whole array is reduced down to the same level of the underperforming panel.

Individual ‘optimisers’ on each panel prevent this happening and combined with a ‘Solar Edge’ inverter, (which monitors and converts the DC from the panels into AC for the mains), allows access to the performance data via the Internet.

Cost was £6,200 as the optimisers and the fancy inverter push the price up, I also went for the more expensive ‘easier on the eye’ all black LG panels.

The return on investment is expected to be around £400 pa FITS (Feed in Tariff), £100 for what I put back into the grid and £200 saving on electricity bills.

So payback period is around 9 years, the system is guaranteed for 20 years and the FIT for 20 years so can’t really go wrong as an investment.

I’ll let folks know via this diary how I get on.

David Pye, Feb 2014